Medical

dendritic spines

den·drit·ic spines

variably long excrescences of nerve cell dendrites, varying in shape from small knobs to thornlike or filamentous processes, usually more numerous on distal dendrite arborizations than on the proximal part of dendritic trunks. Dentritic spines are a preferential site of synaptic axodendritic contact; they are sparse or absent in some types of nerve cells (motor neurons, the large cells of the globus pallidus, and stellate cells of the cerebral cortex), and exceedingly numerous in others such as the pyramidal cells of the cerebral cortex and the Purkinje cells of the cerebellar cortex.
Synonym(s): dendritic thorns, gemmule (2)
Farlex Partner Medical Dictionary © Farlex 2012

den·drit·ic spines

(den-drit'ik spīnz)
Variably long excrescences of nerve cell dendrites, varying in shape from small knobs to thornlike or filamentous processes, usually more numerous on distal dendrite arborizations than on the proximal part of dendritic trunks; they are a preferential site of synaptic axodendritic contact; sparse or absent in some types of nerve cells (motor neurons, the large cells of the globus pallidus, stellate cells of the cerebral cortex), exceedingly numerous in others such as the pyramidal cells of the cerebral cortex and the Purkinje cells of the cerebellar cortex.
Synonym(s): gemmule (2) .
Medical Dictionary for the Health Professions and Nursing © Farlex 2012
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References in periodicals archive
Researchers discovered that when this gene is activated by short bursts of exercise, it promotes small growths on neurons known as dendritic spines -- the site at which synapses form.
In the mammalian cerebral cortex, approximately 80% of excitatory axodendritic synapses are formed on the small protrusions of a neuron's dendrite (dendritic spines).
Additionally, NV-5138 was also observed to increase the number and function of dendritic spines indicating changes in synaptic morphology in neurons comprising the portion of the brain known to be involved in the maintenance of mood.
Pre-clinical studies have shown that chronic treatment with Bryostatin-1 rescues young Fragile X mice from the disorder phenotypes, including normalization of most Fragile X abnormalities in: 1) hippocampal brain-derived neurotrophic factor expression; 2) postsynaptic density-95 levels; 3) transformation of immature dendritic spines to mature synapses; 4) densities of the presynaptic and postsynaptic membranes, and; 5) spatial learning and memory.
In fact, the adult brain is structurally dynamic [35-37], dendritic spines dynamically turn over in the adult brain [37, 38], and learning novel tasks are associated with a further increase in spine turnover [38].
Without sufficient sleep, the dendritic spines that receive signals sent by one brain cell to another were reduced in density and length in a specific region of the hippocampus, restricting the animals' ability to consolidate memories.
Changes within the synapse associated with epilepsy are exerted in dendritic spines [38].
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